I keep all reloads and gift cards. I have no plan on getting rid of them. I figure they take up little space and having them is much better than not having them.

Oh, I also write on each one with a Marker. For the reloads, I write down what day they were purchased and with what cc. Then I write down the date they were used and to what card they were loaded.

For the GC's, I write the date they were used, to what card, the balance (0), and if they were part of a transaction with multiple gc's.

I bit much but it's better if if I ever have a problem.